It’s so easy it’s silly. ARs are fun to work on, even a bit simple. If you think you need a gunsmith to install a trigger for you, think again.
These Timney Triggers aren’t cheap, but they’re not crazy-expensive, either. They’re highly recommendable.
And if you don’t own an AR-15, they make triggers for all sorts of guns. Installing a lightweight trigger, single-stage or otherwise, is one of the simplest ways shrink your groups — especially when ammo is hard to come by. Make your shots count.